hey guys! I've just jumped into the Toshiba world and picked up my first Satellite. After not being able to boot from USB, and having a VERY frustrating experience with technical support, I feel obliged to provide the more clear answer to anyone else searching with this same problem. It is not simply enough to change your boot priority to 'USB'
The answer is you have to disable 'Fast Startup' within windows, and then 'Secure Boot' in the bios, and once you've changed Secure boot to disabled you can then change your Boot option to 'CSM' instead of 'UEFI'. THEN, you can change the boot order priority to 'USB' first and it will actually boot your bootable usb device.
Warning: When you change to 'CSM' boot option, your computer will no longer boot Windows until you go back and change the boot option back to 'UEFI'.
Instructions on how to disable Fast Startup (which then gives you the ability to boot into bios) :
Login to windows, hit the start key and 'Control Panel', then click on Control Panel. Type 'Power' and click on 'Power Options'. Then click 'Change what the power buttons do'. At the top you will see 'Change settings that are currently unavailable'. Click it, and then click Yes. At the bottom of your Power options (scroll down) you will see a 'Shutdown settings' with a 'Turn on fast startup (recommended)'. Uncheck that box and hit save changes.
Reboot and hold down F2 at boot to enter bios
Instructions on how to Disable Secure Boot and change to CSM boot within bios:
Once in bios go to the security tab and change 'Secure Boot' to disabled. Then go to the Advanced tab and press the down arrow key to System Configuration and hit enter. go to 'Boot Mode' and change it from UEFI Boot to CSM Boot.
Hit f10 to save and restart, plug in that bootable USB media and BAM, you've now got a computer working the way it should like almost every other single computer out there!
Just remember that because Toshiba is retarded and wants to over complicate things you will have to go back into bios settings and change CSM Boot back to UEFI Boot in order to boot the OS installed on your internal harddrive.
Hopefully this post will save you all the nightmare you get dealing with incompetent people over the phone who are underpaid in foreign countries to waste your time. Because we all know you NEVER get help until you get to a higher level of support, and these Corporate Tyrants want to charge you money for support for problems they've created with their own poor designs.